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Not getting result : working with completableFuture

I suppose to get the response from two API and then only move forward. To achieve this tried to use completableFuture but ending up in getting NullPointerException, when fetching response from 'result' object.
Infact, completeableFuture basically not have data.
Not able to debug the thread working directly.
public APIResult execute() throws InterruptedException, ExecutionException {
CompletableFuture<TaskChair> completableFutureChair = CompletableFuture.supplyAsync(()->new TaskChair(),executorChair);
CompletableFuture<TaskBottle> completableFutureBottle = CompletableFuture.supplyAsync(()->new TaskBottle(),executorChair);
CompletableFuture<Void> combinedFuture = CompletableFuture.allOf(completableFutureChair, completableFutureBottle);
combinedFuture.get();
TaskChair taskChair = completableFutureChair.get();
TaskBottle taskBottle = completableFutureBottle.get();
List<Chair> chairs = taskChair.getChairs();
List<Bottle> bottles = taskBottle.getBottles();
APIResult result = new APIResult(chairs, bottles);
return result;
}
class TaskChair implements Callable<List<Chair>>{
List<Chair> chairs;
public List<Chair> getChairs() {
return chairs;
}
public void setChairs(List<Chair> chairs) {
this.chairs = chairs;
}
#Override
public List<Chair> call() throws Exception {
chairs = new RestAPI().getChairs();
return chairs;
}
}
public static void main(String[] args) {
RestService service = new RestService();
APIResult result = null;
try {
result = service.execute();
} catch (InterruptedException | ExecutionException e) { }
System.out.println("Chair API Status -> ");
for(Chair chair:result.getChairs()) {
System.out.println(" id : "+chair.getId()+" name : "+ chair.getName());
}
}

Mock FileInputStream using Mockito/PowerMockito without having an existing file

I am writing a JUnit for a method that uses FileInputStream and in the constructor only the file name is passed. The file is created as part of a servlet request and this file is not stored any where.
I am trying to Mock FileInputStream using PowerMockito so that it gives me a mocked file object. Unfortunately I get FileNotFoundException which is valid but I am not sure how to test this method then because the file doesn't exist.
Method under test:
public String viewReport() throws Exception {
this.inputStream = new FileInputStream(DOCUSIGN_REPORT_FILE);
try {
boolean returnReport = validateRequest();
if (returnReport) {
intgList = this.generateViewIntegrationReportData(getESignUIConfig());
this.createCSVFile(intgList, new FileWriter(DOCUSIGN_REPORT_FILE));
} else {
failureResponse(msgs, 400);
return null;
}
} catch (Exception e) {
e.printStackTrace();
msgs.add(new Message(ESignatureIntegrationMessageTypeEnum.MESSAGE_TYPE_ERROR,
UiIntegrationKeyConstants.UI_INTEGRATION_ERROR_CODE_500, UiIntegrationKeyConstants.UI_INTEGRATION_ERROR_TEXT_SERVICE_ERROR));
failureResponse(msgs, 500);
return null;
}
return UiIntegrationKeyConstants.REPORT_REPSONSE;
}
JUnit test so far.
#Test
public void testViewReport() throws Exception {
Map<String, Object> actionMap = new HashMap<>();
actionMap.put("application", "ESignatureIntegrationAction");
ActionContext.setContext(new ActionContext(actionMap));
FileInputStream inputStream = Mockito.mock(FileInputStream.class);
PowerMockito.whenNew(FileInputStream.class).withAnyArguments().thenReturn(inputStream);
action = new ESignatureIntegrationAction();
action.viewReport();
}
I get an exception when the code reaches to new FileInputStream(DOCUSIGN_REPORT_FILE);
Thanks for the help.

I would suggest to refactor your code in a way that allows testing without a mocking framework.
It could look somewhat like this:
public class YourClass {
// ...
public String viewReport() {
try {
boolean isValidRequest = validateRequest();
if (isValidRequest) {
IntegrationReportCsvFileHandler fileHandler = new IntegrationReportCsvFileHandler();
IntegrationReportData inputData = fileHandler.readData(new FileInputStream(DOCUSIGN_REPORT_FILE));
IntegrationReportGenerator generator = new IntegrationReportGenerator();
IntegrationReportData outputData = generator.processData(inputData, getESignUIConfig());
fileHandler.writeReport(outputData, new FileWriter(DOCUSIGN_REPORT_FILE));
} else {
failureResponse(msgs, 400);
return UiIntegrationKeyConstants.FAILURE_RESPONSE;
}
} catch (Exception e) {
e.printStackTrace();
msgs.add(new Message(ESignatureIntegrationMessageTypeEnum.MESSAGE_TYPE_ERROR,
UiIntegrationKeyConstants.UI_INTEGRATION_ERROR_CODE_500, UiIntegrationKeyConstants.UI_INTEGRATION_ERROR_TEXT_SERVICE_ERROR));
failureResponse(msgs, 500);
return UiIntegrationKeyConstants.FAILURE_RESPONSE;
}
return UiIntegrationKeyConstants.REPORT_RESPONSE;
}
// ...
}
public class IntegrationReportData {
// your custom data structure
// may as well just be a List<Data>
// may be different for input and output
}
public class IntegrationReportException extends Exception {
// your custom exception
public IntegrationReportException(String message) { super(exception); }
}
public class IntegrationReportGenerator {
public IntegrationReportData processData(IntegrationReportData data, ESignConfig config) throws IntegrationReportException {
// here's your logic that requires testing
}
}
public class IntegrationReportCsvFileHandler {
public IntegrationReportData readData(InputStream input) throws IOException {
// read data from given input stream
}
public void writeData(IntegrationReportData data, OutputStreamWriter outputWriter) throws IOException {
// write data to given output stream
}
}
That way the IntegrationReportGenerator would be easily testable.

MVEL executeExpression function cannot be concurrent

Run the main function in File2 , the problem is : threads stuck at "rval=MVEL.executeExpression(compiledExpression, vars);" , 10 threads run in sequential order, not parallel , I wanna know why this happened.
PS: I'm using MVEL 2.2 , the latest version
File1:MVELHelper.java
public class MVELHelper {
private static ParserContext _ctx = new ParserContext(false);
//public static Object execute(String expression, Map<String, Object> vars, Databus databus) throws Exception {
public static Object execute(String expression, Map<String, Object> vars) throws Exception {
Object rval = null;
try {
if(vars == null) {
rval = MVEL.eval(expression, new HashMap<String,Object>());
}
else {
rval = MVEL.eval(expression, vars);
}
return rval;
}
catch(Exception e) {
throw new Exception("MVEL FAILED:"+expression,e);
}
}
public static Serializable compile(String text, ParserContext ctx)
throws Exception {
if(ctx == null) {
//ctx = _ctx;
ctx=new ParserContext(false);
}
Serializable exp = null;
try {
exp = MVEL.compileExpression(text, ctx);
//exp = MVEL.compileExpression(text);
}
catch (Exception e) {
throw new Exception("failed to compile expression.", e);
}
return exp;
}
public static Object compileAndExecute(String expression, Map<String, Object> vars) throws Exception {
Object rval = null;
try {
Serializable compiledExpression=compile(expression,null);
System.out.println("[COMPILE OVER, Thread Id="+Thread.currentThread().getId()+"] ");
if(vars == null) {
rval=MVEL.executeExpression(compiledExpression, new HashMap<String,Object>());
//rval = MVEL.eval(exp, new HashMap<String,Object>());
}
else {
//rval=MVEL.executeExpression(compiledExpression, vars,(VariableResolverFactory)null);
rval=MVEL.executeExpression(compiledExpression, vars);
//rval = MVEL.eval(expression, vars);
}
return rval;
}
catch(Exception e) {
throw new Exception("MVEL FAILED:"+expression,e);
}
}
}
File2:ExecThread3.java
public class ExecThread3 implements Runnable{
Map dataMap=null;
public Map getDataMap() {
return dataMap;
}
public void setDataMap(Map dataMap) {
this.dataMap = dataMap;
}
#Override
public void run() {
Map varsMap = new HashMap();
Map dataMap=new HashMap();
dataMap.put("count",100);
varsMap.put("dataMap", dataMap);
String expression="System.out.println(\"[BEFORE Thread Id=\"+Thread.currentThread().getId()+\"] \"+dataMap.get(\"count\"));"+
"Thread.sleep(3000);"+
"System.err.println(\"[AFTER Thread Id=\"+Thread.currentThread().getId()+\"] \"+dataMap.get(\"count\"));";
try {
//MVEL.compileExpression(expression);
MVELHelper.compileAndExecute(expression, varsMap);
}
catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
for(int k=0;k<10;k++){
ExecThread3 execThread=new ExecThread3();
new Thread(execThread).start();
}
}
}

assertThat error message for unexpected exception

I have this sort of JUnit test:
#Test
public void testNullCheck() {
String res = someMethod();
assertThat("This is the someMethodTest", res, is(notNullValue()));
}
If someMethod() throws an exception I get a stack trace but the "This is the someMethodTest" is not printed as assertThat() is not called. Is there a somewhat elegant JUnit/hamcrest way to print a custom error message? Eventually I want this in a parametrized test to print the parameter for which the test fails. Note, I don't want to test for a specific exception.

You could create an own Rule that replaces the exception:
public class NiceExceptions implements TestRule {
public Statement apply(final Statement base, final Description description) {
return new Statement() {
#Override
public void evaluate() throws Throwable {
try {
base.evaluate();
} catch (AssumptionViolatedException e) {
throw e;
} catch (Throwable t) {
throw new YourNiceException(t);
}
}
};
}
}
public class YourTest {
#Rule
public final TestRule niceExceptions = new NiceExceptions();
#Test
public void yourTest() {
...
}
}

What about this way:
#Test
public void testNullCheck() {
try{
String res = someMethod();
assertThat("This is the someMethodTest", res, is(notNullValue()));
}catch( Exception e /*or any especific exception*/ ){
fail("This is the someMethodTest Error " + e.getMessage() );
}
}

Using Stefan Birkner's suggestion this is what I came up with. Comments welcome.
package my.test;
import org.junit.internal.AssumptionViolatedException;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
public class ExceptionCatcher implements TestRule {
String msg;
#Override
public Statement apply(final Statement base, final Description description) {
return new Statement() {
#Override
public void evaluate() throws Throwable {
try {
base.evaluate();
} catch (AssumptionViolatedException e) {
throw e;
} catch (AssertionError e){
throw e;
} catch (Throwable t) {
msg = t.getMessage() + "; " + msg;
Throwable cause = t.getCause();
if (cause == null)
cause = t;
StackTraceElement[] stackTrace = cause.getStackTrace();
Throwable t1 = null;
try {
t1 = t.getClass().newInstance();
t1 = t.getClass().getDeclaredConstructor(String.class).newInstance(msg);
t1 = t.getClass().getDeclaredConstructor(String.class, Throwable.class).newInstance(msg, t);
t1.setStackTrace(stackTrace);
throw t1;
} catch (Throwable ignore) {
t1.setStackTrace(stackTrace);
throw t1;
}
}
}
};
}
public void setMsg(String msg) {
this.msg = msg;
}
}
And in the test case:
#Rule
public final ExceptionCatcher catcher = new ExceptionCatcher();
#Before
public void setUp() throws Exception {
catcher.setMsg("....");
}
#Test
public void testNullCheck() {
String res = someMethod();
assertThat("This is the someMethodTest", res, is(notNullValue()));
}

why Threads get blocked when i use Apache-Commons-Pool?

Here is my demo:
PoolableObjectFactoryImpl.java
public class PoolableObjectFactoryImpl implements PoolableObjectFactory<Result> {
private static Logger logger = Logger.getLogger("BackgroundLog");
#Override
public void activateObject(Result obj) throws Exception {
logger.info("==activate result.==");
obj.setResult(-999);
}
#Override
public void destroyObject(Result obj) throws Exception {
logger.info("==destroy result.==");
obj = null;
}
#Override
public Result makeObject() throws Exception {
logger.info("==make result.==");
Result result = new Result();
return result;
}
#Override
public void passivateObject(Result obj) throws Exception {
logger.info("==passivate result.==");
obj.setResult(-999);
}
#Override
public boolean validateObject(Result obj) {
/*if(obj.getResult() == -999){
logger.info("==validate result true.==");
return true;
}else{
logger.info("==validate result false.==");
return false;
}*/
logger.info("==validate result true.==");
return true;
}
}
ThreadPool.java
public class ThreadPool extends GenericObjectPool {
private static Logger logger = Logger.getLogger("BackgroundLog");
private static ThreadPool pool = null;
private Map<String, String> map = getConfig();
private ThreadPool() {
this.setFactory(new PoolableObjectFactoryImpl());
this.setMaxActive(Integer.parseInt(map.get("maxActive")));
this.setWhenExhaustedAction(Byte.valueOf(map.get("whenExhaustedAction")));
this.setMaxWait(Long.parseLong(map.get("maxWait")));
this.setMaxIdle(Integer.parseInt(map.get("maxIdle")));
this.setTestOnBorrow(Boolean.valueOf(map.get("testOnBorrow")));
this.setTestOnReturn(Boolean.valueOf(map.get("testOnReturn")));
this.setTimeBetweenEvictionRunsMillis(Long.parseLong(map.get("timeBetweenEvictionRunsMillis")));
this.setNumTestsPerEvictionRun(Integer.parseInt(map.get("numTestsPerEvictionRun")));
this.setMinEvictableIdleTimeMillis(Long.parseLong(map.get("minEvictableIdleTimeMillis")));
this.setTestWhileIdle(Boolean.valueOf(map.get("testWhileIdle")));
}
public static ThreadPool getInstance() {
if (pool == null) {
synchronized (ThreadPool.class) {
if (pool == null) {
logger.info("thread pool is initialized.");
pool = new ThreadPool();
}
}
}
return pool;
}
/**
*
* <p>Title: getConfig</p>
* <p>Description: get pool configuration</p>
* #return
*/
public Map<String, String> getConfig() {
Map<String, String> map = new HashMap<String, String>();
Properties props = new Properties();
try {
InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("pool.properties");
props.load(in);
Enumeration en = props.propertyNames();
while (en.hasMoreElements()) {
String key = (String) en.nextElement();
map.put(key, props.getProperty(key));
}
in.close();
} catch (Throwable t) {
logger.error(t.getMessage(), t);
}
return map;
}
}
Result.java
public class Result {
private int result;
public Result(){
}
public int getResult(){
return this.result;
}
public void setResult(int result){
this.result = result;
}
}
Test.java
public class Test implements Runnable {
private static Logger logger = Logger.getLogger("BackgroundLog");
private String name = null;
public Test(String name){
this.name = name;
}
public String getName(){
return this.name;
}
public void setName(String name){
this.name = name;
}
#Override
public void run() {
ThreadPool pool = ThreadPool.getInstance();
for(int i=0;i<1000;i++){
try {
Result result = (Result)pool.borrowObject();
logger.info("numActive: "+ pool.getNumActive()+"\t"+"numIdle: "+pool.getNumIdle());
logger.info("thread "+getName()+" "+i+" borrow object from pool "+result.getResult()+".");
result.setResult(0);
pool.returnObject(result);
logger.info("return object to pool.");
Thread.sleep(100);
} catch (Exception e) {
logger.info("thread "+getName()+" "+i);
e.printStackTrace();
}
}
}
public static void main(String[] args) {
for(int i=0;i<50;i++){
Thread t = new Thread(new Test("t"+i));
t.start();
}
}
}
Next is the configuration properties:
Next is the threads view from Jprofiler when it has 4 threads:
After Test.java is running a few minutes,some threads keep beling blocked,only one is still running but does not print any log.I don't really understand thread thing.
can anyone explain why? how to avoid threads being blocked?

Consider posting logs of an execution cycle.
Did you try commenting Thread.sleep line, because sleep will hold onto the lock it has acquired till the thread is in sleep mode.

Try replacing "Thread.sleep(100);" with:
try {
synchronized (this) {
this.wait(200);
}
} catch (InterruptedException e) {
}